1. Field of the Invention
The present invention relates to telecommunication devices. In particular, the present invention relates to a system and a method for displaying telephone numbers and character strings on a display of a telecommunication device, such as a mobile telephone or a landline telephone.
2. Description of the Related Art
International Telecommunication Union (ITU) Recommendation E.123: “Notation for national and international telephone numbers” defines a standard way to write telephone numbers. E.123 recommends specific telephone number formats for national and international telephone numbers. Exemplary telephone numbers in the formats recommended by E.123 are shown below:
National notation(042) 123 4567International notation+31 42 123 4567
E.123 recommends that a hyphen (-), space ( ), or period (.) be used to visually separate groups of numbers. Use of such characters tends to be country specific with a space character ( ) being the most commonly used. Parentheses in a telephone number are used to indicate digits that are sometimes not dialed.
International Direct Dialing (IDD) prefix is recommended as an international prefix that is required to dial a call from a country listed to another country. The IDD prefix is followed by a country code for the country that is being called. The IDD prefix situation in many countries has been regularly changing. Some countries have multiple IDD prefixes, with each IDD prefix used by a different long-distance carrier. To overcome the problem of changing and different IDD prefixes on mobile telephones, the Groupe Spécial Mobile (GSM), a study group formed by the Conference of European Posts and Telegraphs (CEPT), adopted from its inception a plus sign (+) as a generic IDD prefix for GSM mobile telephones, although country specific IDD prefixes still usually work. A separate “+” key is now rarely seen on GSM telephones. Instead, a + sign character is usually generated by pressing and holding the 0 or * key, or pressing the 0 or * key multiply times rapidly.
While E.123 recommends formats for national and international telephone numbers, telephone equipment, such as a mobile telephone, conventionally displays telephone numbers as a continuous string of numbers that is not readily interpreted by a user. Consequently, what is needed is a way to display a telephone number with appropriate country-code hyphenation so that a user can readily interpret an international telephone number.